Presidential races take place on many levels, some visible, others more shrouded. As the clock runs down, both sides make tough decisions about which states to compete in and which to abandon. Here are five things to watch in the final 58 days:

1 Electoral map: The roster of battleground states has not changed much, but one that Republicans had hoped to put in play appears to have broken decisively: Pennsylvania. Romney spent time and money in the state, which went Democratic in the past five elections, but GOP strategists now say it seems out of reach. Wisconsin, which has 10 electoral votes and is home to Romney's running mate, Rep. Paul Ryan, may offer Romney the best chance to expand his options. Romney had hoped to put at least a few more states into safer Republican territory. North Carolina, which Obama narrowly carried in 2008, is at the top of the list. But the state is still competitive enough that Romney and GOP groups feel compelled to keep spending on advertising there, complicating their hopes of making Wisconsin and Michigan more competitive.

Some Democrats say winning Florida remains a reach for Obama, but his presence there this weekend suggests that the White House has not given up.

2 Debates: In a race that has featured little significant movement between the candidates, the debates are taking on even greater importance. For weeks, Obama and Romney have been preparing for their encounters on Oct. 3 in Denver; Oct. 16 in Hempstead, N.Y.; and Oct. 22 in Boca Raton, Fla.

The president, whose advisers know him to procrastinate before preparing for big moments, has been studying his rival's positions from the primary. Romney may be a little further ahead in his preparations. His aides began putting blocks of debate-preparation time into his schedule shortly after he emerged from the primaries in the spring. He started formal practice sessions last week in Vermont.

3 Ads and messages: After spending the spring and summer trying to turn Romney's success as a business executive from a positive to a negative, characterizing him as uncaring about the middle class, Obama's aides and allies intend to graft their portrayal onto specific policy areas. They suggested that one attack, building on the president's argument that Romney intends essentially to privatize Medicare, would contend that the Republican ticket's next target would be another immensely popular program, Social Security. In the past, Ryan has supported adding personal investment accounts to Social Security, a fundamental shift in the program that most Democrats say would leave seniors vulnerable to swings in the financial markets.

Having studied the 2004 race, when President George W. Bush won re-election after defining Kerry on his terms during the spring and summer, Obama's advisers are convinced that the most crucial advertising period of the campaign is already over, and that they accomplished what they had to. Romney's team is betting that early ad spending is largely wasted, and that a final and furious campaign will move the race in his direction when it most counts, at the end. The campaign's belief is that continued disappointing economic data will feed its slogan, "Obama Isn't Working." Republicans say they also intend to link their broader economic message to specific policies: cutting spending and reducing the national debt, working to ensure the solvency of Medicare, cutting regulations and avoiding tax increases.

4 Ballot: There is one factor that has yet to get much attention but could influence the outcome: third-party candidacies in many states, most notably that of former Gov. Gary Johnson of New Mexico, the Libertarian Party's presidential nominee. Johnson, who advocated free markets, fewer wars and the legalization of marijuana during his brief run for the Republican nomination, hardly shows up in polls. But he is on more than three dozen state ballots and trying for more. Advisers to Johnson said he had the most potential to cut into Romney's support in Florida and to have some influence in Nevada, New Hampshire and Arizona. They said he had the most potential to eat into Obama's support in New Mexico, Colorado, Iowa, Oregon and Wisconsin.

5 Money: For the first time since the advent of public financing after Watergate, neither major-party candidate will accept matching funds, forcing both to keep raising money right up to Election Day. At the end of July, when the last figures were available, Romney and the related Republican Party committees had about $186 million on hand, compared with about $124 million for Obama and the Democrats. Obama's advisers have expressed concerns that the Romney war chest, combined with well-financed Republican super PACs, will swamp them and Priorities USA Action when it comes to advertising. But much of the Obama campaign's money is going into its sophisticated voter-identification and get-out-the-vote operation, which is fully up and running while Romney rushes to build his own.

NEW YORK TIMES